HUMAN TROPHOBLASTIC ISOENZYME (LACTATE DEHYDROGENASE-Z) ASSOCIATED WITH CHORIOCARCINOMA

  • 1 January 1980
    • journal article
    • research article
    • Vol. 40  (2) , 283-287
Abstract
A unique electrophoretic form of lactate dehydrogenase (LDH-Z), formerly observed in a choriocarcinoma cell line (JEG-3) and 1st-trimester placenta, was the same as that produced in hydatidiform mole and term placenta. LDH-Z was also observed in 2nd-trimester placenta, choriocarcinoma metastasized to the liver, and 5 of 5 additional independently derived (from different patients) choriocarcinoma cell lines. The only exception to the production of LDH-Z in a choriocarcinoma was in the cell line BEWO, which was established from the same tumor as JEG-3. Since BEWO has been in culture for over 200 passages more than any of the independently derived lines, its lack of LDH-Z is viewed as consistent with the loss of certain expressional characteristics upon such long-term culture. Analysis of JEG-3 subclones revealed the expression of LDH-Z to be independent of the products of the LDH-A genetic locus. Present data do not allow determination as to whether LDH-Z is the product of a newly discovered LDH locus or a modified form of the product of the LDH-B locus. LDH-Z has not been observed in other human tissues, nor in homogenates prepared from > 60 cell lines established from a wide variety of human neoplasms. LDH-Z is an isozyme associated with human choriocarcinoma and apparently is indicative of the trophoblastic origin of the cells.